Range is decisive for the dimensioning of the battery and therefore for the vehicle costs. And: high range plus low vehicle costs are the most important factors for the acceptance of e-cars. Thermal management plays a decisive role in this dilemma, because we want to keep the car warm in winter too.
Cooling in summer, heating in winter: the electric drive, HV battery, power electronics and vehicle occupants have different temperature requirements and these must therefore be actively controlled. In winter in particular, the heat required for the interior and battery leads to high power consumption. Thermal management therefore plays an important role in the vehicle's efficiency and therefore its range.
The integrated direct thermal management system from MAHLE offers an efficient, innovative and cost-effective solution. This system includes a heat pump function that uses all available heat sources, such as waste heat from the powertrain and ambient heat, as a source to optimize the range in winter, even when the cabin has a high heating requirement. The performance and efficiency benefits have been proven in vehicle tests.
Special attention is paid to component integration with modules on the refrigerant and coolant side - for further cost savings.
MAHLE has secured two major orders for thermal management modules for electric cars. The total order volume for both projects is just under EUR 1.5 billion. MAHLE combines previously individually installed components in thermal management modules that control the temperature of the battery, vehicle interior, powertrain and power electronics.
The modules work much more efficiently than their individual parts and can significantly increase the range of an electric car by up to 20 percent as well as the charging speed.
In both modules, MAHLE has combined its individual components such as the electric compressor, heat exchanger, refrigerant valves and other components into a single unit. One of the modules is particularly highly integrated, as it connects the refrigerant circuit with the coolant circuits. This ensures that the battery, drivetrain and vehicle interior are supplied with sufficient heat in winter and optimally cooled in summer.
Caption: Powerhouse: The thermal management module from MAHLE reduces installation space and costs. It works much more efficiently and can increase the range of an electric car by up to 20 percent.
To date, there is no standardized system architecture for heat pumps on the market. In general, a distinction can be made between two large concept families: direct and indirect heat pump systems. This classification is based on the way in which the heat is transferred to the interior. In indirect systems, hot coolant and a corresponding heat exchanger are used to heat the air. In the direct system approach developed by MAHLE, the heat is transferred directly from the coolant to the cabin air.
This system design has a considerable efficiency advantage below zero degrees Celsius ambient temperature. Overall, the system can be operated in a variety of cooling and heating modes.
This includes cooling the vehicle cabin, the electric drive and the battery, as well as efficiently heating the cabin by recovering heat from the environment, the electric drive and the battery.
The data in the graph shows a comparison of the energy consumption of heat pump systems in different vehicles. It clearly shows that - compared to the best-tested system (vehicle C) - the MAHLE Direct Thermal System (DTS) has a 20 percent lower energy consumption.
Compared to a vehicle without a heat pump, i.e. a vehicle that heats the vehicle cabin with an electric heater alone, this results in a range increase of 20 percent.
The main components of the DTS are a two-row cooling module with a low-temperature cooler and an external heat exchanger (OHX), an air conditioning unit with heat pump heater and evaporator as well as an intelligent R/D module as a combination of the refrigerant high-pressure receiver with several valves and a cooling control module, which includes a cooler as well as coolant pumps and valves. An internal heat exchanger (IHX) is also part of the thermal system.